chore: use early conn to support real ws 0-rtt

adapter/outboundgroup/urltest.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/Dreamacro/clash/adapter/outbound"
+	"github.com/Dreamacro/clash/common/callback"
 	"github.com/Dreamacro/clash/common/singledo"
 	"github.com/Dreamacro/clash/component/dialer"
 	C "github.com/Dreamacro/clash/constant"
@@ -38,10 +39,20 @@ func (u *URLTest) DialContext(ctx context.Context, metadata *C.Metadata, opts ..
 	c, err = proxy.DialContext(ctx, metadata, u.Base.DialOptions(opts...)...)
 	if err == nil {
 		c.AppendToChains(u)
-		u.onDialSuccess()
 	} else {
 		u.onDialFailed(proxy.Type(), err)
 	}
+
+	c = &callback.FirstWriteCallBackConn{
+		Conn: c,
+		Callback: func(err error) {
+			if err == nil {
+				u.onDialSuccess()
+			} else {
+				u.onDialFailed(proxy.Type(), err)
+			}
+		},
+	}
 	return c, err
 }